cell biology transcription Flashcards
the expression of genes into proteins involves 2 processes:
transcription and translataion
( the regulation occurs at each step as:
1- chromatin structure
2- transcription initiation
3- mRNA stability
4- trasncriptiing processing )
when cell needs to produce certain proteins , it activates the region of the genome encoding for that protein and produces —- copies of that dna in the form of —–
- multiple
- mRNA
multiple copies of —- are used to translate the genetic code into protein aka the photocopy portion of the cell through the action of the cells protein manufacturing machinery called —-
- mRNA
- ribosomes
—– expands the quantity of a given protein and it gives an important control point for regulating when and how much proteins gets made
mRNA
- important for copying the genetic info from dna ( primary a storage form of the genome )
- contributes to the formation of ribosomes ( ribosomes are particles important for the sythesis of new proteins )
- help assemble new polypeptides by bringing individuals amino acids ( tRNA )
are all fucntions for —–
RNA
rna is — stranded of 2/3degree structure and is found in —— and the sugar is —- while dna is only found in —-
- single stranded
- nucleas and cytoplasm
- ribose sugar
- nucleas
—– is a type of rna that codes for proteins when produced by transcprtion , is translated m contains instruction for protein scythes and is found in nucleus and cytoplasm
mrna
—- is a type of rna that form a basic structure of the ribosome and catalyse protein sythesis
rRNA
—- is a type of rna by which it function in variety of nuclear process including splicing the pre-mrna
snRNA ( small nuclear rna )
—- type of rna that function in variety of diverse cellular process including regulation of gene expression , x- chromosome inactivation and protein transport
ncRNA ( non coding rna)
transcription begins at the —- at the end of the —- region , trancrption ends at the —– site
- transcription start site ( TSS)
- promoter region
- termination site
—- are regions of the dna upstream of the TSS which lead the initiation of transcpriton , each gene has a unique one and the 2 different types are:
- promotors
- basal promotor and enhancer element
—- recognised by the proteins that will aid transcription ( aka transcription factors )
enhancer
— bound by a key transcriptional enzyme rna polymerase II and basal transcription factors required ( which is required for rna pol II bidding )
basal
—– essential for trancpriton of all genes and fucntions recruit in RNA pol II , binds basal/general trancripton factors first and these once are bound to en pol II will bind . example:
- basal promotor
- TATA box which is common ( 20-30 base pairs from transcriptional start site and can bind basal Tfs and RNA pol II )